Google+ is getting some improvements on the desktop site to make keeping on top of your notifications a little easier. You’ll be able to check out updates and other alerts in a dedicated page, instead of being confined to the smaller area that we’re used.
In the normal notification tray, you’ll also be able to filter out unread notifications from what you’ve already cleared, which can be useful if you’ve got a ton of alerts popping up.
If you’re not seeing the change yet, keep an eye for it to roll out over the next few days.
source: Google Plus